Comparison Phase
A two arm, 12 week comparative clinical study assessing
tolerability of Rebif® and Betaseron®, including the primary endpoint of the first 21
injections of full dose therapy for Rebif® (Weeks 5 - 11) and Betaseron® (Weeks 7 – 12).

Extension Phase
After Week 12, all patients will be offered to continue the safety
extension on Rebif® (New Formulation) up to Week 36 (an additional period of 24 weeks).

Key Inclusion Criteria
To be eligible for inclusion into this study, the subjects must fulfill all of the following criteria:

Subject with diagnosis of RRMS according to McDonald criteria (see Appendix H for definition)

Subject is between 18 and 60 years old inclusive

Subject is willing to follow study procedures

Subject has given written informed consent

Female subjects must be neither pregnant nor breast-feeding and must lack childbearing potential, as defined by either: i. Being post-menopausal or surgically sterile, or ii. Using an effective contraceptive for the duration of the study.

Confirmation that the subject is not pregnant must be established by a negative serum hCG test within 7 days prior to start of study treatment. A pregnancy test is not required if the subject is post-menopausal, surgically sterile or otherwise is unable to conceive.

Key Exclusion Criteria
To be eligible for inclusion in this study the subjects must not meet any of the following criteria:

Subject has had any prior interferon beta therapy (either beta-1b or beta-1a)

Subject received any other approved disease modifying therapy for MS (glatiramer
acetate) or any cytokine or anti-cytokine therapy within the 3 months prior to Study Day .

Subject received immunomodulatory or immunosuppressive therapy (including but not
limited to cyclophosphamide, cyclosporin, methotrexate, azathioprine, linomide,
mitoxantrone, teriflunomide, natalizumab, laquinimod, Campath and cladribine) within the
12 months prior to Study Day 1.

Subject has previously received total lymphoid irradiation.

Subject has known allergy to natural or recombinant interferon or any other component of
formulation excipient(s) of Rebif® or Betaseron®: Mannitol, Poloxamer 188, Methionine,
Benzyl alcohol or Albumin (human).

Use of any other injectable medications on a regular basis during the week prior to the
screening period or during the screening or treatment periods. Receiving a single
injection for treatment or prophylaxis of a condition unrelated to the patient’s multiple
sclerosis or the patient’s Rebif® or Betaseron® therapy (e.g. receiving a influenza or
pneumococcus vaccination) is acceptable.

History of any chronic pain syndrome.

Subject has any other disease apart from MS that could better explain the subjects signs
and symptoms.

Subject has complete transverse myelitis or bilateral optic neuritis.

Subjects who used any investigational drug or experimental procedure within 12 weeks
prior to visit 1.

Subject has inadequate liver function, defined by a total bilirubin, aspartate aminotransferase (AST) or alanine aminotransferase (ALT) or alkaline phosphatase >
2.5 times the upper limit of the normal values.